Illinois Class D Water License Test with
Questions & Answers
Two Towers are both 125 feet high, when full, contain 122 feet of water. Tower 1 holds 150,000
gallons. Tower 2 holds 500,000 gallons. Each has a pressure gauge at the base. Which will
register the most pressure in psi?
Both will be equal
If the water level in tower 1 is 118 feet what will the pressure reading be at the base
51.1 psi
What is the definition of potable water
Water that does not contain objectable pollution, contamination, or infective agents and is
considered safe for drinking
What is the first item used when installing a service line to a customer?
Corporation stop
If a meter to a residence is located in the basement what should be located between the water
main and the house
curb stop
A 5/8" x 3/4" water meter serves a residence. Over a period of years the meter __________ in
recording actual water used
Decreases
To isolate part of a distribution system what type of valve is commonly used?
Gate valve
Trihalomethanes (THMs) are caused by?
Reaction of chlorinated water with numeric materials found in surface water sources
The longer the contact time water and chlorine residuals enjoy the ________ the THM level will
probably be
Higher
THM's should be eliminated from finished water because they cause ?
Cancer
, The maximum contaminant level for THM's is?
.080 mg/l
When collecting THM samples one sample must be taken at a site where the water has been in
the distribution system the longest time
True
An applicant for a class d test who has graduated high school but has no approved training
credits must have ____________ "hands on" experience
6 months
What type of water main is most likely to become contaminated from gasoline saturated soil
PVC
What type of materials must not be used as backfill for water mains?
Cinders
Nitrate in levels above _________ mg/L can cause "blue baby" disease
10
A boil order must be issued if systems pressure drops below 20 psi or if contaminated of any part
of the system is suspected. Why?
It is a regulation of the IEPA, and to protect the health of water consumers
A boil order should be issued for?
Until further notice
Upon the issuance of a boil order the IEPA regional office should be notified of the order because
________________?
It's a state regulation
The "C" factor of a pipe is _______________?
The smoothness of the interior of a pipe
The higher the "C" factor of a pipe the _____________ the pipe and the greater the carrying
capacity of the pipe
Smoother
A distribution system that is "looped" instead of having dead ends will help prevent
Tastes and odors, "dirty" water, and chlorine depletion
Questions & Answers
Two Towers are both 125 feet high, when full, contain 122 feet of water. Tower 1 holds 150,000
gallons. Tower 2 holds 500,000 gallons. Each has a pressure gauge at the base. Which will
register the most pressure in psi?
Both will be equal
If the water level in tower 1 is 118 feet what will the pressure reading be at the base
51.1 psi
What is the definition of potable water
Water that does not contain objectable pollution, contamination, or infective agents and is
considered safe for drinking
What is the first item used when installing a service line to a customer?
Corporation stop
If a meter to a residence is located in the basement what should be located between the water
main and the house
curb stop
A 5/8" x 3/4" water meter serves a residence. Over a period of years the meter __________ in
recording actual water used
Decreases
To isolate part of a distribution system what type of valve is commonly used?
Gate valve
Trihalomethanes (THMs) are caused by?
Reaction of chlorinated water with numeric materials found in surface water sources
The longer the contact time water and chlorine residuals enjoy the ________ the THM level will
probably be
Higher
THM's should be eliminated from finished water because they cause ?
Cancer
, The maximum contaminant level for THM's is?
.080 mg/l
When collecting THM samples one sample must be taken at a site where the water has been in
the distribution system the longest time
True
An applicant for a class d test who has graduated high school but has no approved training
credits must have ____________ "hands on" experience
6 months
What type of water main is most likely to become contaminated from gasoline saturated soil
PVC
What type of materials must not be used as backfill for water mains?
Cinders
Nitrate in levels above _________ mg/L can cause "blue baby" disease
10
A boil order must be issued if systems pressure drops below 20 psi or if contaminated of any part
of the system is suspected. Why?
It is a regulation of the IEPA, and to protect the health of water consumers
A boil order should be issued for?
Until further notice
Upon the issuance of a boil order the IEPA regional office should be notified of the order because
________________?
It's a state regulation
The "C" factor of a pipe is _______________?
The smoothness of the interior of a pipe
The higher the "C" factor of a pipe the _____________ the pipe and the greater the carrying
capacity of the pipe
Smoother
A distribution system that is "looped" instead of having dead ends will help prevent
Tastes and odors, "dirty" water, and chlorine depletion
